New Rowland Criterion 2-chassis battery pre

I also have a 501 that I use for my center channel. It improved a lot when I got the PC-1, but was still definately behind my 301´s.

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But believe me, it improved even more when I later on connected the PC-1 to my Burmester 948 which is powered by a Nordost Odin power cord!! Now I think the 501 are almost in the same league as my 301´s

sorry I don't understand ???

Mark, here is what I know about the control knob on Criterion.. . .

The knob first of all has 2 distinct ways of operating. . .

turning the knob adjusts volume for primary and secondary zones, right to left balance, input offsets, output offsets, menu scroll.

Pressing the volume knob utilizes the knob as a selector for entering menu mode and activating a selection.

I do not know what chip/module the volume control is based on, (it may be an HP part but I am not sure(, but it is an optically encoded system, therefore the knob can be rotated continuously clockwise and counterclockwise without ever reaching a stop position. When Criterion is turned on, volume is always at 0dB. The volume is speed sensitive: turning the knob slowly or pressing single taps on the remote control volume buttons changes volume in 0.5dB increments. . . rotating the volume control faster or holding down remote volume buttons changes volume in 1.5dB increments. . . the loudness range is 0dB to 99.5dB. Per my notes, precision/stability is said to be within 0.01dB. Furthermore, the volume control is said to cause the audio bandwidth to remain unrestricted at all gain levels, without the volume becoming a bandpass filter at low SPLs. Also when using the volume to change offset values, balance, and volume for secondary zone, the volume knob remains velocity sensitive.

It is my understanding that the volume control does not act on the audio section directly. . . The volume control is in the control chassis.. . it communicates with a microprocessor controller in the same chassis. . . when a volume change is requested, the microprocessor awakens a communication bus. . . sends appropriate control codes to the audio circuit in the audio chassis that alters the gain of the OPA1632, then powers down the data bus until new controls are required. So the controller is always offline, unless it is needed to change a preamplification parameter. . . and the change takes place in a fraction of a second.

From an experience point of view the volume control is extremely quiet. it turns with a little less friction than on Capri. I can hear very soft volume change clicks only when rotating the knob quickly beyond the 93dB mark on the display. . . which is something that I do only if no music is playing. The background noise is essentially completely quiet up to the top of the gain scale.

Let me know if you need more information. . . but this is all I know up to now. Guido

Ok, let me explain more in detail. This is how my 501 amp for the center channel gets it power:
Wall outlet -> Nordost Odin power cord -> Burmester 948 AC conditioner -> Nordost Brahma power cord -> Rowland PC-1 -> T+A custom built power cord -> Rowland 501.

The main reason why I have the Odin cord from wall to the Burmester 948 AC condition is because I also have my two channel front end gear connected to it. So get me right, I did not buy the Odin with the purpose to use it with the 501! That us just a bonus the way I have set it up.

I have not connected my 301´s to the 948 of two reasons; the 948 has not enough capacity for that I think and also I have two dedicated AC lines for my 301´s. The power cords I have for the 301´s (Wireworld Gold Electra) unfortunately are not in the same league as Nordost Odin. That is the reason I said that the performance from my 501 are almost in the same league as my 301´s and why I also think I need two more Odins (for mye 301´s).
Hope this helped.

thanks

Thank you Guido re the description of the volume control. The Synergy is similiar in that it also uses a optical encoder under microprocessor control. I am curious about what electronic circuit (whether chip or discrete) is used to implement the volume control. Cheers Mark